Position/force controller, and position/force control method and storage medium

ABSTRACT

A position/force controller includes a function-dependent force/speed distribution conversion unit that, on the basis of speed, position and force information relating to a position based on an action of an actuator and control reference information, performs a conversion to distribute control energy to at least one of speed or position energy and force energy according to a function that is being realized. A control amount calculation unit calculates at least one of a speed or position control amount and a force energy on the basis of at least one of the speed or position energy and the force energy distributed by the force/speed distribution conversion unit. An integration unit integrates speed or position control amount with force control amount and, to return an output to the actuator, performs a reverse conversion on the speed or position control amount and the force control amount and determines an input to the actuator.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional application of U.S. application Ser.No. 15/022,878, filed Mar. 17, 2016, which is a U.S. National Phaseapplication of International Application No. PCT/JP2014/073083, filedSep. 2, 2014 and which is based on prior Japanese Patent Application No.2013-194704, filed Sep. 19, 2013. The entire contents of all theabove-identified applications are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a position/force controller thatcontrols positions and forces of a control object, and to aposition/force control method and storage medium.

BACKGROUND ART

Heretofore, in the context of an ageing society and suchlike, there havebeen strong calls to replace humans with robots for tasks that take timeand effort.

However, operations of conventional robots are lacking in environmentaladaptability and flexibility; human-like movements have not yet beenappropriately realized.

Efforts have been made to use time-series position information and forceinformation acquired by a master/slave system to artificially reproducethe movements of actuators.

However, mechanical impedance is always constant during thesereproductions; as yet, adaptability to environmental changes such aspositions in an environment, sizes and mechanical impedances has beenlacking.

Techniques relating to robots that perform remote control throughmaster/slave systems are recited in, for example, Patent Document 1 andPatent Document 2.

Patent Document 1: PCT International Publication No. WO2005/109139

Patent Document 2: Japanese Unexamined Patent Application, PublicationNo. 2009-279699

DISCLOSURE OF THE INVENTION

Both a high level of environmental adaptability through high-precisionforce control and sampling of movements in a human coordinate system bya system with many degrees of freedom are extremely important forrealizing the replacement of humans with robots for tasks that take timeand effort.

This has not yet been realized by conventional techniques.

In other words, conventional techniques have scope for improvement inregard to appropriately realizing human-like movements by a robot.

Means for Solving the Problems

A position/force controller according to an aspect of the presentinvention includes:

a position detector that detects information relating to a positionbased on an action of an actuator;

a function-dependent force/speed distribution converter that, on thebasis of speed or position information and force informationcorresponding to the information relating to the position and on thebasis of information serving as a reference for control, performs aconversion to distribute control energy to speed or position energy andforce energy in accordance with a function that is being realized;

a position control amount calculator that calculates a speed or positioncontrol amount on the basis of the speed or position energy distributedby the function-dependent force/speed distribution converter;

a force control amount calculator that calculates a force control amounton the basis of the force energy distributed by the function-dependentforce/speed distribution converter;

an integrator that integrates the speed or position control amount withthe force control amount and, in order to return an output of theintegration to the actuator, performs a reverse conversion on the speedor position control amount and the force control amount and determinesan input to the actuator,

wherein the speed or position energy and the force energy can berespectively separately controlled.

Effects of the Invention

According to the present invention, a technique for more appropriatelyrealizing human-like movements by a robot may be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an overview of a basic principlerelating to the present invention.

FIG. 2 is a schematic diagram showing an overview of control when aforce-sense transmission function is defined at a function-dependentforce/speed distribution conversion block FT.

FIG. 3 is a schematic diagram showing an overview of a master/slavesystem that includes a master device and a slave device at which theforce-sense transmission function is employed.

FIG. 4 is a schematic diagram showing an overview of control when a pickand place function is defined at the function-dependent force/speeddistribution conversion block FT.

FIG. 5 is a schematic diagram showing an overview of a robot arm systemincluding a first arm and a second arm at which the pick and placefunction is employed.

FIG. 6 is a schematic diagram showing an overview of control when abolt-turning learning and reproduction function is defined at thefunction-dependent force/speed distribution conversion block FT.

FIG. 7A is a schematic diagram showing an overview of a master/slavesystem including a master finger-form robot and a slave finger-formrobot at which the bolt-turning learning and reproduction function isemployed.

FIG. 7B is a schematic diagram showing a finger mechanism of thefinger-form robots.

FIG. 8 is a schematic diagram showing basic structure of aposition/force controller 1 in accordance with the present invention.

FIG. 9 is a schematic diagram showing structures of the position/forcecontroller 1 that realize the force-sense transmission function.

FIG. 10 is a schematic diagram showing structures of the position/forcecontroller 1 that realize the pick and place function.

FIG. 11 is a schematic diagram showing structures of the position/forcecontroller 1 that realize the bolt-turning learning and reproductionfunction.

FIG. 12A shows a case in which a time series of positions of the wiresW1 to W4 is stored.

FIG. 12B shows a case in which coordinate conversion results accordingto Expression (4) are stored.

FIGS. 13A to 13I are descriptive diagrams showing an overview ofrealizing an adaptable function.

FIG. 14 is a schematic diagram showing structures of the position/forcecontroller 1 that can replace a function.

FIG. 15 is a schematic diagram showing an overview of control of aforce-sense transmission function that uses scaling in frequency ranges.

FIG. 16 is a schematic diagram showing a situation in which theforce-sense transmission function is realized with a body in a virtualspace.

FIG. 17 is a schematic diagram showing an overview of control when theforce-sense transmission function is realized with the body in thevirtual space.

FIGS. 18A to 18D are schematic diagrams showing a situation in which thepresent invention is applied to surgical forceps.

FIG. 19 is a schematic diagram showing a master device and a slavedevice that are connected by wireless.

FIG. 20 is a block diagram showing structures of a slave device 400 thatis connected by wireless to a master device.

FIG. 21 is a diagram showing a data structure for high-speedcommunications between the master device and the slave device.

FIG. 22 is a timing chart showing a communication sequence between themaster device and slave device that are connected by wireless.

FIG. 23 is a schematic diagram showing an overview of creating adatabase of human operations.

FIG. 24 is a schematic diagram showing an overview of offsetting infunction-dependent force/speed distribution conversion.

PREFERRED MODE FOR CARRYING OUT THE INVENTION

Herebelow, an embodiment of the present invention is described withreference to the attached drawings.

First, a basic principle employed in the position/force controller,position/force control method and program according to the presentinvention is described.

Human-like movements are constituted by the particular functioning ofindividual joints and the like separately or in combination.

Accordingly, the term “movement” as used in the present embodimentherebelow refers to an integrated function in which the particular“functions” of portions of the human body are realized as constituentelements. For example, a movement associated with flexing and extensionof a middle finger (a movement to turn a bolt or the like) is anintegrated function in which the functions of respective joints of themiddle finger are constituent elements.

(Basic Principle)

The basic principle of the present invention is that any movement can bemathematically represented by three elements: a force origin, a speed(or position) origin and a conversion representing the movement.Therefore, by control energy from an ideal force origin and an idealspeed (position) origin, which have a duality relationship, beingsupplied to a control object system in accordance with a set ofvariables defined by a conversion and a reverse conversion, a sampledhuman body movement may be constituted, reconstructed and/or amplifiedto reversibly and automatically realize (reproduce) the body movement.

FIG. 1 is a schematic diagram showing an overview of the basic principlerelating to the present invention.

The basic principle as shown in FIG. 1 represents control rules of anactuator that can be used for realizing human-like movements. Anoperation of the actuator may be determined by performing computationsin at least one of a position (or speed) domain and a force domain,using a current position of the actuator as an input.

That is, the basic principle of the present invention is represented ascontrol rules including a control object system S, a function-dependentforce/speed distribution conversion block FT, at least one of an idealforce origin block FC and an ideal speed (position) origin block PC, anda reverse conversion block IFT.

The control object system S is a robot that operates through anactuator/actuators. The control object system S controls each actuatoron the basis of acceleration or the like. The control object system Srealizes functions of one or plural portions of a human body. Providedthe control object system S employs control rules for realizing thesefunctions, the concrete structure of the control object system S doesnot necessarily need to be in a form that resembles the human body. Forexample, the control object system S may be a robot that moves a link ina one-dimensional sliding operation with an actuator.

The function-dependent force/speed distribution conversion block FT is ablock that defines a conversion of control energy in the speed(position) and force domains, which is specified in accordance with afunction of the control object system S. Specifically, thefunction-dependent force/speed distribution conversion block FT definesa coordinate conversion whose inputs are a value serving as a referencefor the function of the control object system S (a reference value) andthe current position of an actuator. The coordinate conversion is,generally speaking, a conversion of an input vector whose elements are areference value of speed (position) and a current speed (position) to anoutput vector constituted with a speed (position) for calculating acontrol target value of speed (position), and a conversion of an inputvector whose elements are a reference value of force and a current forceto an output vector constituted with a force for calculating a controltarget value of force. To be specific, the coordinate conversion by thefunction-dependent force/speed distribution conversion block FT can begeneralized and expressed as in the following Expressions (1) and (2).

$\begin{matrix}{\begin{pmatrix}{\overset{.}{x}}_{1} \\{\overset{.}{x}}_{2} \\\vdots \\{\overset{.}{x}}_{n - 1} \\{\overset{.}{x}}_{n}\end{pmatrix} = {\begin{pmatrix}h_{1a} & h_{1b} & \ldots & h_{1{({m - 1})}} & h_{1m} \\h_{2a} & h_{2b} & \ldots & h_{2{({m - 1})}} & h_{2m} \\\vdots & \vdots & \ddots & \vdots & \vdots \\h_{{({n - 1})}a} & h_{{({n - 1})}b} & \ldots & h_{{({n - 1})}{({m - 1})}} & h_{{({n - 1})}m} \\h_{na} & h_{nb} & \ldots & h_{n{({m - 1})}} & h_{n\; m}\end{pmatrix}\begin{pmatrix}{\overset{.}{x}}_{a} \\{\overset{.}{x}}_{b} \\\vdots \\{\overset{.}{x}}_{m - 1} \\{\overset{.}{x}}_{m}\end{pmatrix}}} & (1) \\{\begin{pmatrix}f_{1} \\f_{2} \\\vdots \\f_{n - 1} \\f_{n}\end{pmatrix} = {\begin{pmatrix}h_{1a} & h_{1b} & \ldots & h_{1{({m - 1})}} & h_{1m} \\h_{2a} & h_{2b} & \ldots & h_{2{({m - 1})}} & h_{2m} \\\vdots & \vdots & \ddots & \vdots & \vdots \\h_{{({n - 1})}a} & h_{{({n - 1})}b} & \ldots & h_{{({n - 1})}{({m - 1})}} & h_{{({n - 1})}m} \\h_{na} & h_{nb} & \ldots & h_{n{({m - 1})}} & h_{n\; m}\end{pmatrix}\begin{pmatrix}f_{a} \\f_{b} \\\vdots \\f_{m - 1} \\f_{m}\end{pmatrix}}} & (2)\end{matrix}$

In Expression (1), x′₁ to x′_(n) (n is an integer that is at least 1)represent speed vectors for calculating a state value of speed, x′_(a)to x′_(m) (m is an integer that is at least 1) represent vectors whoseelements are a reference value and a speed based on an action of theactuator (a speed of a moving element of the actuator or a speed of anobject being moved by the actuator), and h_(1a) to h_(nm) representelements of a conversion matrix representing the function. In Expression(2), f″₁ to f″_(n) (n is an integer that is at least 1) represent forcevectors for calculating a state value of force, and f″_(a) to f″_(m) (mis an integer that is at least 1) represent vectors whose elements are areference value and a force based on an action of the actuator (a forceof a moving element of the actuator or a force of the object being movedby the actuator).

By the coordinate conversion by the function-dependent force/speeddistribution conversion block FT being specified in accordance with thefunction to be realized, various movements may be realized and movementsmay be reproduced with scaling.

That is, in the basic principle of the present invention, thefunction-dependent force/speed distribution conversion block FT“converts” a variable of an actuator unit (a variable in real space) toa set of variables (variables in virtual space) for the whole systemrepresenting the function to be realized, and distributes control energyto speed (position) control energy and force control energy. Therefore,in contrast to a case in which control is performed using unmodifiedvariables of actuator units (variables in real space), the speed(position) control energy and force control energy may be givenseparately.

The ideal force origin block FC is a block that performs computations inthe force domain in accordance with the coordinate conversion defined bythe function-dependent force/speed distribution conversion block FT. Theideal force origin block FC sets a target value relating to force inperforming a computation on the basis of the coordinate conversiondefined by the function-dependent force/speed distribution conversionblock FT. The target value is set as a fixed value or a variable value,depending on the function being realized. For example, if the functionbeing realized is the same as the function represented by the referencevalue, the target value is set to zero, and if scaling is to be applied,information representing the function being reproduced is set to amagnified or reduced value.

The ideal speed (position) origin block PC is a block that performscomputations in the speed (position) domain in accordance with thecoordinate conversion defined by the function-dependent force/speeddistribution conversion block FT. The ideal speed (position) originblock PC sets a target value relating to speed (position) in performinga computation on the basis of the coordinate conversion defined by thefunction-dependent force/speed distribution conversion block FT. Thetarget value is set as a fixed value or a variable value, depending onthe function being realized. For example, if the function being realizedis the same as the function represented by the reference value, thetarget value is set to zero, and if scaling is to be applied,information representing the function being reproduced is set to amagnified or reduced value.

The reverse conversion block IFT is a block that converts values in thespeed (position) and force domains to values in an input domain for thecontrol object system S (for example, voltage values, current values orthe like).

According to the basic principle, when position information of anactuator of the control object system S is inputted to thefunction-dependent force/speed distribution conversion block FT, thefunction-dependent force/speed distribution conversion block FT usesspeed (position) and force information obtained on the basis of thisposition information and applies respective control rules according tothe function in the position and force domains. A force according to thefunction is computed at the ideal force origin block FC, a speed(position) according to the function is computed at the ideal speed(position) origin block PC, and control energy is allocated to each ofthe force and speed (position).

Computation results from the ideal force origin block FC and the idealspeed (position) origin block PC are information representing controltargets of the control object system S. These computed values areconverted to actuator input values by the reverse conversion block IFTand the actuator input values are inputted to the control object systemS.

As a result, the actuator of the control object system S executes anoperation corresponding to the function defined by thefunction-dependent force/speed distribution conversion block FT and therobot operation that is the objective is realized.

Thus, in the present invention, a human-like movement by a robot may bemore appropriately realized.

Defined Function Examples

Now, specific examples of functions defined by the function-dependentforce/speed distribution conversion block FT are described.

The function-dependent force/speed distribution conversion block FTdefines a coordinate conversion whose objects are a speed (position) andforce obtained on the basis of a current position of an actuator (aconversion from real space to a virtual space according to the functionbeing realized).

At the function-dependent force/speed distribution conversion block FT,the inputs are a speed (position) and force derived from the currentposition and a speed (position) and force that are reference values ofthe function; the function-dependent force/speed distribution conversionblock FT applies the control rules for each of speed (position) andforce in terms of accelerations.

That is, a force of the actuator is expressed as the product of mass andacceleration, and a speed (position) of the actuator is expressed byintegrating acceleration. Therefore, the current position of theactuator may be acquired and the function that is the objective may berealized by controlling speeds (positions) and forces via theacceleration domain.

Herebelow, concrete examples of various functions are described.

(Force-Sense Transmission Function)

FIG. 2 is a schematic diagram showing an overview of control when aforce-sense transmission function is defined at the function-dependentforce/speed distribution conversion block FT. FIG. 3 is a schematicdiagram showing an overview of a master/slave system that includes amaster device and a slave device at which the force-sense transmissionfunction is employed.

As shown in FIG. 2, a function that transfers an operation of the masterdevice to the slave device and that feeds back to the master device areaction force from a body against the slave device (a bilateral controlfunction) may be realized as the function defined by thefunction-dependent force/speed distribution conversion block FT.

In this case, the coordinate conversion by the function-dependentforce/speed distribution conversion block FT can be expressed as in thefollowing Expressions (3) and (4).

$\begin{matrix}{\begin{pmatrix}{\overset{.}{x}}_{p} \\{\overset{.}{x}}_{f}\end{pmatrix} = {\begin{pmatrix}1 & {- 1} \\1 & 1\end{pmatrix}\begin{pmatrix}{\overset{.}{x}}_{m} \\{\overset{.}{x}}_{s}\end{pmatrix}}} & (3) \\{\begin{pmatrix}f_{p} \\f_{f}\end{pmatrix} = {\begin{pmatrix}1 & {- 1} \\1 & 1\end{pmatrix}\begin{pmatrix}f_{m} \\f_{s}\end{pmatrix}}} & (4)\end{matrix}$

In Expression (3), x′_(p) represents a speed for calculating a statevalue of speed (position) and x′_(f) represents a speed relating to astate value of force. Further, x′_(m) represents a reference value (ofan input from the master device) of speed (a differential value of thecurrent position of the master device) and x′_(s) represents a currentspeed (a differential value of the current position) of the slavedevice. In expression (4), f_(p) represents a force relating to thestate value of speed (position) and f_(f) represents a force forcalculating the state value of force. Further, f_(m) represents areference value (of an input from the master device) of force and f_(s)represents a current force of the slave device.

(Pick and Place Function)

FIG. 4 is a schematic diagram showing an overview of control when thepick and place function is defined at the function-dependent force/speeddistribution conversion block FT. FIG. 5 is a schematic diagram showingan overview of a robot arm system including a first arm and a second armat which the pick and place function is employed.

As shown in FIG. 4, a function to grip (pick) a body such as a workpieceor the like, convey it to a target position, and release (place) it maybe realized as a function (the pick and place function) defined by thefunction-dependent force/speed distribution conversion block FT.

In this case, the coordinate conversion by the function-dependentforce/speed distribution conversion block FT can be expressed as in thefollowing Expressions (5) and (6).

$\begin{matrix}{\begin{pmatrix}{\overset{.}{x}}_{mani} \\{\overset{.}{x}}_{grasp}\end{pmatrix} = {\begin{pmatrix}1 & 1 \\1 & {- 1}\end{pmatrix}\begin{pmatrix}{\overset{.}{x}}_{1} \\{\overset{.}{x}}_{2}\end{pmatrix}}} & (5) \\{\begin{pmatrix}f_{mani} \\f_{grasp}\end{pmatrix} = {\begin{pmatrix}1 & 1 \\1 & {- 1}\end{pmatrix}\begin{pmatrix}f_{1} \\f_{2}\end{pmatrix}}} & (6)\end{matrix}$

In Expression (5), x′_(mani) represents a speed for calculating a statevalue of speed (position) and x′_(grasp) represents a speed relating toa state value of force. Further, x′₁ represents a speed (a differentialof the current position) of the first arm and x′₂ represents a speed(differential value of the current position) of the second arm. InExpression (6), f_(mani) represents a force relating to a state value ofspeed (position) and f_(grasp) represents a force for calculating astate value of force. Further, f₁ represents a reaction force that thefirst arm receives from the body and f₂ represents a reaction force thatthe second arm receives from the body.

(Bolt-Turning Learning and Reproduction Function)

FIG. 6 is a schematic diagram showing an overview of control when abolt-turning learning and reproduction function is defined at thefunction-dependent force/speed distribution conversion block FT. FIG. 7Aand FIG. 7B are schematic diagrams showing a robot at which thebolt-turning learning and reproduction function is employed. FIG. 7A isa schematic diagram showing an overview of a master/slave systemincluding a master finger-form robot and a slave finger-form robot atwhich the bolt-turning learning and reproduction function is employed.FIG. 7B is a schematic diagram showing a finger mechanism of thefinger-form robots.

As shown in FIG. 6, the bolt-turning learning and reproduction functionthat fastens a bolt by flexing and extending a finger may be realized asa function defined by the function-dependent force/speed distributionconversion block FT.

In this case, the coordinate conversion by the function-dependentforce/speed distribution conversion block FT can be expressed as in thefollowing Expressions (7) and (8).

$\begin{matrix}{\begin{pmatrix}{\overset{.}{x}}_{a\; 1} \\{\overset{.}{x}}_{a\; 2} \\{\overset{.}{x}}_{a\; 3} \\{\overset{.}{x}}_{\tau\; 1} \\{\overset{.}{x}}_{\tau\; 2} \\{\overset{.}{x}}_{\tau\; 3} \\{\overset{.}{x}}_{t\; 1} \\{\overset{.}{x}}_{t\; 2}\end{pmatrix}\begin{pmatrix}\frac{2}{11} & \frac{2}{11} & \frac{4}{11} & \frac{- 3}{11} & \frac{- 3}{11} & \frac{4}{11} & \frac{2}{11} & \frac{2}{11} \\\frac{3}{11} & \frac{3}{11} & \frac{- 5}{11} & \frac{1}{11} & \frac{1}{11} & \frac{- 5}{11} & \frac{3}{11} & \frac{3}{11} \\\frac{1}{2} & \frac{- 1}{2} & 0 & 0 & 0 & 0 & \frac{- 1}{2} & \frac{1}{2} \\1 & 1 & 1 & {- 1} & 1 & {- 1} & {- 1} & {- 1} \\1 & 1 & {- 1} & 0 & 0 & 1 & {- 1} & {- 1} \\1 & {- 1} & 0 & 0 & 0 & 0 & 1 & {- 1} \\1 & 1 & 2 & 4 & 0 & 0 & 0 & 0 \\0 & 0 & 0 & 0 & 4 & 2 & 1 & 1\end{pmatrix}\begin{pmatrix}{\overset{.}{x}}_{1} \\{\overset{.}{x}}_{2} \\{\overset{.}{x}}_{3} \\{\overset{.}{x}}_{4} \\{\overset{.}{x}}_{5} \\{\overset{.}{x}}_{6} \\{\overset{.}{x}}_{7} \\{\overset{.}{x}}_{8}\end{pmatrix}} & (7) \\{\begin{pmatrix}f_{a\; 1} \\f_{a\; 2} \\f_{a\; 3} \\f_{\tau\; 1} \\f_{\tau\; 2} \\f_{\tau\; 3} \\f_{t\; 1} \\f_{t\; 2}\end{pmatrix} = {\begin{pmatrix}\frac{2}{11} & \frac{2}{11} & \frac{4}{11} & \frac{- 3}{11} & \frac{- 3}{11} & \frac{4}{11} & \frac{2}{11} & \frac{2}{11} \\\frac{3}{11} & \frac{3}{11} & \frac{- 5}{11} & \frac{1}{11} & \frac{1}{11} & \frac{- 5}{11} & \frac{3}{11} & \frac{3}{11} \\\frac{1}{2} & \frac{- 1}{2} & 0 & 0 & 0 & 0 & \frac{- 1}{2} & \frac{1}{2} \\1 & 1 & 1 & {- 1} & 1 & {- 1} & {- 1} & {- 1} \\1 & 1 & {- 1} & 0 & 0 & 1 & {- 1} & {- 1} \\1 & {- 1} & 0 & 0 & 0 & 0 & 1 & {- 1} \\1 & 1 & 2 & 4 & 0 & 0 & 0 & 0 \\0 & 0 & 0 & 0 & 4 & 2 & 1 & 1\end{pmatrix}\begin{pmatrix}f_{1} \\f_{2} \\f_{3} \\f_{4} \\f_{5} \\f_{6} \\f_{7} \\f_{8}\end{pmatrix}}} & (8)\end{matrix}$

In Expression (7), x′_(a1) represents a speed-correspondent valuerelating to an angle of an MP joint, x′_(a2) represents aspeed-correspondent value relating to an angle of a PIP joint, andx′_(a3) represents a speed-correspondent value relating to an angle of aDIP joint. Further, x′_(τ1) represents a speed-correspondent valuerelating to a torque of the MP joint, x′_(τ2) represents aspeed-correspondent value relating to a torque of the PIP joint, andx′_(τ3) represents a speed-correspondent value relating to a torque ofthe DIP joint. Meanwhile, x′_(t1) represents a speed-correspondent valuerelating to tension in wires W1 to W4 of the master finger-form robot,x′_(t2) represents a speed-correspondent value relating to tension inwires W5 to W8 of the slave finger-form robot, x′₁ to x′₄ representrespective speed-correspondent values of the wires W1 to W4 connected tothe master finger-form robot, and x′₅ to x′₈ represent respectivespeed-correspondent values of the wires W5 to W8 connected to the slavefinger-form robot. The angle of the MP joint, angle of the PIP joint andangle of the DIP joint are defined as shown by θ₁ to θ₃ in FIG. 7B. InExpression (8), f_(a1) represents a force-correspondent value relatingto the angle of the MP joint, f_(a2) represents a force-correspondentvalue relating to the angle of the PIP joint, and f_(a3) represents aforce-correspondent value relating to the angle of the DIP joint.Further, f_(τ1) represents a force-correspondent value relating to thetorque of the MP joint, f_(τ2) represents a force-correspondent valuerelating to the torque of the PIP joint, and f_(τ3) represents aforce-correspondent value relating to the torque of the DIP joint.Meanwhile, ft1 represents a force-correspondent value relating to thetension in wires W1 to W4 of the master finger-form robot, f_(t2)represents a force-correspondent value relating to the tension in wiresW5 to W8 of the slave finger-form robot, f₁ to f₄ represent respectiveforce-correspondent values of the wires W1 to W4 connected to the masterfinger-form robot, and f₅ to f₈ represent respective force-correspondentvalues of the wires W5 to W8 connected to the slave finger-form robot.

(Basic Structure of the Position/Force Controller)

Now, basic structure of the position/force controller 1 employing thebasic principle of the present invention is described.

FIG. 8 is a schematic diagram showing the basic structure of theposition/force controller 1 in accordance with the present invention.

In FIG. 8, the structure of the position/force controller 1 includes areference value input section 10, a control section 20, a driver 30, anactuator 40 and a position sensor 50.

The position/force controller 1 operates as a slave device in responseto operations of a master device, which is not shown in FIG. 8. Theposition/force controller 1 inputs detection results of a positionsensor disposed at an actuator of the master device and operates inaccordance with a function.

A function with which the position/force controller 1 is equipped may bevariously changed by replacing a coordinate conversion defined by thefunction-dependent force/speed distribution conversion block FT in thecontrol section 20, as described below.

The reference value input section 10 inputs to the control section 20values to serve as reference values for each function (reference values)that are provided to the position/force controller 1. For example, thereference values are a time series of detection values outputted by aposition sensor disposed at the actuator of the master device If thetime series of detection values is to be inputted to the control section20 as reference values from the master device in real time, thereference value input section 10 may be structured by a communicationsinterface (communications I/F). Alternatively, if the time series ofdetection values from the master device is stored in advance,sequentially read out and inputted to the control section 20 asreference values, the reference value input section 10 may be structuredby a storage device such as memory, a hard disc or the like.

The control section 20 performs overall control of the position/forcecontroller 1 and is structured by an information processing device suchas a central processing unit (CPU) or the like.

The control section 20 is equipped with the functions of thefunction-dependent force/speed distribution conversion block FT, theideal force origin block FC, the ideal speed (position) origin block PCand the reverse conversion block IFT shown in FIG. 1.

That is, the control section 20 inputs the time series of detectionvalues detected by the position sensor of the master device via thereference value input section 10. This time series of detection valuesexpresses operations of the master device. The control section 20applies the coordinate conversion specified in accordance with thefunction to information on speeds (positions) and forces calculated fromthe inputted detection values (positions).

The control section 20 performs computations in the speed (position)domain on the speeds (positions) for calculating the state value ofspeed (position) provided by the coordinate conversion. Similarly, thecontrol section 20 performs computations in the force domain on theforces for calculating the state value of force provided by thecoordinate conversion. The control section 20 applies dimensionstandardization processing, to accelerations or the like, to thecalculated computation results in the speed (position) domain andcomputation results in the force domain. The control section 20 thenapplies a reverse conversion of the coordinate conversion specified inaccordance with the function. Thus, the control section 20 converts thecalculated computation results in the speed (position) domain andcomputation results in the force domain to values in a domain of inputsto the actuator.

The driver 30 converts the values in the domain of inputs to theactuator, to which the reverse conversion has been performed by thecontrol section 20, to specific control command values for the actuator40 (voltage values, current values or the like), and outputs thesecontrol command values to the actuator 40.

The actuator 40 performs driving in response to the control commandvalues inputted from the driver 30, thus controlling a position of acontrol object.

The position sensor 50 detects positions of the control objectcontrolled by the actuator 40 and outputs the detection values to thecontrol section 20.

Thus, the position/force controller 1 with this structure convertsspeeds (positions) and forces obtained from the positions of the controlobject detected by the position sensor 50 to state values in the speed(position) domain and the force domain by the coordinate conversioncorresponding to the function. Hence, control energy is distributed toeach of speed (position) and force in accordance with the function.Then, the reverse conversion is performed on the respective state valuesto find control command values, and the actuator 40 is driven by thedriver 30 in response to these control command values.

Thus, by detecting positions of the control object, the position/forcecontroller 1 may calculate the state values of speed (position) andforce that are necessary for realizing the function that is theobjective, and by driving the actuator 40 on the basis of these statevalues, the position/force controller 1 may control the position andforce of the control object into a state that is an objective.

Moreover, by replacing the coordinate conversion corresponding to afunction in the control section 20, the position/force controller 1 mayrealize different functions. For example, various functions may berealized by the position/force controller 1, by coordinate conversionscorresponding to plural functions being stored in accordance with therespective functions in a storage device provided at the position/forcecontroller 1 and the coordinate conversion corresponding to one of thefunctions being selected in accordance with an objective.

The position/force controller 1 may use reference values inputted to thecontrol section 20 and acquired values of position and force that areinputted in real time from a master device. In this case, theposition/force controller 1 may be controlled in conjunction withoperations of the master device in real time.

Alternatively, the position/force controller 1 may use reference valuesinputted to the control section 20 and acquired values of time series ofposition and force of a master device or a slave device that have beenacquired and stored in advance. In this case, the position/forcecontroller 1 may use operations of the master device prepared beforehandas reference values to realize the function. In other words, theposition/force controller 1 may reproduce a function that is anobjective in a situation in which the master device is not present.

(A Concrete Example of the Position/Force Controller 1)

Now, a concrete structural example of the position/force controller 1 isdescribed.

As described above, the position/force controller 1 may realize variousfunctions by replacing coordinate conversions in accordance withfunctions defined by the control section 20.

Below, a structural example of the position/force controller 1 isdescribed for cases of realizing the force-sense transmission functionaccording to FIG. 2, the pick and place function according to FIG. 4,and the bolt-turning learning and reproduction function according toFIG. 6.

(Structural Example of the Position/Force Controller 1 Realizing theForce-Sense Transmission Function)

FIG. 9 is a schematic diagram showing structures of the position/forcecontroller 1 that realize the force-sense transmission function.

The structure of the position/force controller 1 in FIG. 9 includes amaster device 100A, a slave device 100B and a personal computer (PC)100C.

The master device 100A is structured by the actuator 40, incorporatingthe driver 30 and the position sensor 50.

The master device 100A is equipped with a movable shaft 41A that isslidable in one direction. The movable shaft 41A is moved by anoperator. Positions of the movable shaft 41A are detected by theposition sensor 50 and the detection values are outputted to the PC100C.

The actuator 40 of the master device 100A is controlled by the PC 100C.The position/force controller 1 according to FIG. 9 is equipped with abilateral control function. Operations of the actuator 40 of the masterdevice 100A are controlled by the PC 100C in response to forces withwhich the slave device 100B touches against a body.

Similarly to the master device 100A, the slave device 100B is structuredby another of the actuator 40, incorporating others of the driver 30 andthe position sensor 50.

The slave device 100B is equipped with a movable shaft 41B that isslidable in one direction. The movable shaft 41B is moved by theactuator 40. Positions of the movable shaft 41B are detected by theposition sensor 50 and the detection values are outputted to the PC100C.

The PC 100C is equipped with a communications interface 110, whichincludes the functions of the reference value input section 10, and thecontrol section 20.

The communications interface 110 receives detection values of theposition sensors 50 that are inputted from the master device 100A andthe slave device 100B, and outputs the detection values to the controlsection 20. The communications interface 110 outputs values ofacceleration for controlling the actuators 40 of the master device 100Aand the slave device 100B, which are inputted to the communicationsinterface 110 from the control section 20, to the master device 100A andthe slave device 100B.

In the case of the position/force controller 1 that realizes theforce-sense transmission function, a coordinate conversion expressed asin Expression (2) is defined at the control section 20. Consequently,control is performed to a state in which a difference between a positionof the actuator 40 of the master device 100A and a position of theactuator 40 of the slave device 100B is zero. Further, control isperformed to a state in which a force that the operator applies to theactuator 40 of the master device 100A and a reaction force from a bodyacting on the actuator 40 of the slave device 100B have anaction-reaction relationship (mutually equal and in oppositedirections).

Therefore, controls performed on the master device 100A may beaccurately reproduced at the slave device 100B, and reaction forces frombodies inputted to the slave device 100B may be accurately transmittedto the master device 100A.

(Structural Example of the Position/Force Controller 1 Realizing thePick and Place Function)

FIG. 10 is a schematic diagram showing structures of the position/forcecontroller 1 that realize the pick and place function. The structure ofthe position/force controller 1 in FIG. 10 includes an arm unit 200Astructuring a first arm, an arm unit 200B structuring a second arm, anda personal computer (PC) 200C.

The arm unit 200A is structured by an arm portion 201A and the actuator40, incorporating the driver 30 and the position sensor 50.

The arm unit 200A is equipped with a movable shaft (not shown in thedrawing) that is slidable in one direction. The arm portion 201A isfixed to a distal end portion of the movable shaft. Positions of the armportion 201A (that is, positions of the movable shaft) are detected bythe position sensor 50 and the detection values are outputted to the PC200C.

The actuator 40 of the arm unit 200A is controlled by the PC 200C.Specifically, the arm portion 201A is controlled by the PC 200C so as toabut against an object with a specified force, retain the objecttogether with an arm portion 201B in this state, and move the object.

The arm unit 200B is structured by the arm portion 201B and, similarlyto the arm unit 200A, another of the actuator 40, incorporating othersof the driver 30 and the position sensor 50.

The PC 200C is equipped with a communications interface 210, whichincludes the functions of the reference value input section 10, and thecontrol section 20.

The communications interface 210 receives detection values of theposition sensors 50 that are inputted from the arm unit 200A and the armunit 200B, and outputs the detection values to the control section 20.The communications interface 210 outputs values of acceleration forcontrolling the actuators 40 of the arm unit 200A and the arm unit 200B,which are inputted to the communications interface 210 from the controlsection 20, to the arm unit 200A and the arm unit 200B.

In the case of the position/force controller 1 that realizes the pickand place transmission function, a coordinate conversion expressed as inExpression (3) is defined at the control section 20. Consequently,control is performed to a state in which a difference between a reactionforce vector from a body acting on the actuator 40 of the arm unit 200Aand a reaction force vector from the body acting on the actuator 40 ofthe arm unit 200B, which is to say a gripping force, is at a specifiedtarget value. Further, control is performed to a state in which the sumof a position of the arm portion 201A of the arm unit 200A (adisplacement of the arm portion 201A from a reference position) and aposition of the arm portion 201B of the arm unit 200B (a displacement ofthe arm portion 201B from a reference position), which is to say thecenter between the two arms, is at a specified target value.

Thus, operations are performed to move the arm portion 201A of the armunit 200A and the arm portion 201B of the arm unit 200B toward and awayfrom another, and control is performed to a state in which the armportion 201A and the arm portion 201B abut against an object with thesame force. In this state, the object may be gripped and conveyed to atarget position by the arm portion 201A and the arm portion 201B beingmoved in the same direction.

(Structural Example of the Position/Force Controller 1 Realizing theBolt-Turning Learning and Reproduction Function)

FIG. 11 is a schematic diagram showing structures of the position/forcecontroller 1 that realize the bolt-turning learning and reproductionfunction. The structure of the position/force controller 1 in FIG. 11includes a finger-form robot 300A that serves as a master device, afinger-form robot 300B that serves as a slave device, and a personalcomputer (PC) 300C.

The finger-form robot 300A is structured by a finger mechanism portion310A, wires W1 to W4 that are connected to portions of the fingermechanism portion 310A, and actuators 40 a to 40 d that perform controlto pull on the wires W1 to W4.

The finger mechanism portion 310A is equipped with a base portion 311A,which corresponds to a human metacarpal, a proximal phalanx portion 312Acorresponding to a proximal phalanx, a middle phalanx portion 313Acorresponding to a middle phalanx, a distal phalanx portion 314Acorresponding to a distal phalanx, an MP joint portion 315Acorresponding to an MP joint, a PIP joint portion 316A corresponding toa PIP joint, and a DIP joint portion 317A corresponding to a DIP joint.One end of the wire W1 is connected to a back-of-hand side of the distalphalanx portion 314A.

The wire W1 passes along the back-of-hand side of the finger mechanismportion 310A, and the other end of the wire W1 is connected to an outputshaft of the actuator 40 a. Therefore, when the wire W1 is pulled on bythe actuator 40 a, an operation to extend the finger of the fingermechanism portion 310A is realized.

One end of the wire W2 is connected to a palm-of-hand side of the distalphalanx portion 314A. The wire W2 is guided out to the back-of-hand sideat the middle phalanx portion 313A, and the other end of the wire W2 isconnected to an output shaft of the actuator 40 b. Therefore, when thewire W2 is pulled on by the actuator 40 b, force is applied in thedirection of flexing the finger at the DIP joint portion and in thedirection of extending the finger at the PIP joint and the MP joint.

One end of the wire W3 is connected to the palm-of-hand side of themiddle phalanx portion 313A. The wire W3 is guided out to theback-of-hand side at the proximal phalanx portion 312A, and the otherend of the wire W3 is connected to an output shaft of the actuator 40 c.Therefore, when the wire W3 is pulled on by the actuator 40 c, force isapplied in the direction of flexing the finger at the PIP joint and inthe direction of extending the finger at the MP joint.

One end of the wire W4 is connected to the palm-of-hand side of theproximal phalanx portion 312A. The wire W4 passes along the palm-of-handside of the finger mechanism portion 310A, and the other end of the wireW4 is connected to an output shaft of the actuator 40 d. Therefore, whenthe wire W4 is pulled on by the actuator 40 d, an operation to flex thefinger is realized, pivoting the proximal phalanx portion 312A about theMP joint portion 315A.

The actuators 40 a to 40 d are controlled by the PC 300C. Specifically,values for realizing positions/angles and attitudes of the respectiveportions of the finger-form robot 300A, rotary torques, and tensions inthe wires W1 to W4 are inputted from the PC 300C to the actuators 40 ato 40 d. Control is performed to pull on the wires W1 to W4 in responseto these input values.

The actuators 40 a to 40 d each incorporate one of the driver 30 and theposition sensor 50. Positions of the wires W1 to W4 are detected by theposition sensors 50 of the actuators 40 a to 40 d and these detectionvalues are outputted to the PC 300C.

The finger-form robot 300A is moved to track the operations (movements)of a human finger and these operations (movements) are sampled in theform of a time series of detection values of the position sensors 50 ofthe actuators 40 a to 40 d.

Specifically, respective portions of the finger mechanism portion 310Aof the finger-form robot 300A are fixed to corresponding portions of thehuman finger (that is, the distal phalanx portion 314A to the distalphalanx, the middle phalanx portion 313A to the middle phalanx, and theproximal phalanx portion 312A to the proximal phalanx), putting thefinger mechanism portion 310A into a state that tracks operations of thehuman finger.

Of the distal phalanx portion 314A and the distal phalanx, the middlephalanx portion 313A and the middle phalanx, and the proximal phalanxportion 312A and the proximal phalanx, it is sufficient to fix thedistal phalanx portion 314A to the distal phalanx and fix one other ofthese portions. Fixing of the remaining one portion may be omitted.

The finger-form robot 300B is structured by a finger mechanism portion310B, wires W5 to W8 that are connected to portions of the fingermechanism portion 310B, and actuators 40 e to 40 h that perform controlto pull on the wires W5 to W8.

The finger mechanism portion 310B is equipped with a base portion 311B,which corresponds to a human metacarpal, a proximal phalanx portion 312Bcorresponding to a proximal phalanx, a middle phalanx portion 313Bcorresponding to a middle phalanx, a distal phalanx portion 314Bcorresponding to a distal phalanx, an MP joint portion 315Bcorresponding to an MP joint, a PIP joint portion 316B corresponding toa PIP joint, and a DIP joint portion 317B corresponding to a DIP joint.

One end of the wire W5 is connected to the back-of-hand side of theproximal phalanx portion 312B. The wire W5 passes along the back-of-handside of the finger mechanism portion 310B, and the other end of the wireW5 is connected to an output shaft of the actuator 40 e. Therefore, whenthe wire W5 is pulled on by the actuator 40 e, an operation to extendthe finger is realized, pivoting the proximal phalanx portion 312B aboutthe MP joint portion 315B. One end of the wire W6 is connected to theback-of-hand side of the middle phalanx portion 313B.

The wire W6 is guided out to the palm-of-hand side at the proximalphalanx portion 312B, and the other end of the wire W6 is connected toan output shaft of the actuator 40 f. Therefore, when the wire W6 ispulled on by the actuator 40 f, an operation to extend the finger isrealized, pivoting the middle phalanx portion 313B about the PIP jointportion 316B.

One end of the wire W7 is connected to the back-of-hand side of thedistal phalanx portion 314B. The wire W7 is guided out to thepalm-of-hand side at the middle phalanx portion 313B, and the other endof the wire W7 is connected to an output shaft of the actuator 40 g.Therefore, when the wire W7 is pulled on by the actuator 40 g, anoperation to extend the finger is realized, pivoting the distal phalanxportion 314B about the DIP joint portion 317B. One end of the wire W8 isconnected to the palm-of-hand side of the distal phalanx portion 314B.

The wire W8 passes along the palm-of-hand side of the finger mechanismportion 310B, and the other end of the wire W8 is connected to an outputshaft of the actuator 40 h. Therefore, when the wire W8 is pulled on bythe actuator 40 h, an operation to flex the finger of the fingermechanism portion 310B is realized.

The actuators 40 e to 40 h are controlled by the PC 300C. Specifically,values for realizing positions/angles and attitudes of the respectiveportions of the finger-form robot 300B, rotary torques, and tensions inthe wires W5 to W8 that have been sampled as operations of thefinger-form robot 300A are inputted from the PC 300C to the actuators 40e to 40 h. Control is performed to pull on the wires W5 to W8 inresponse to these input values.

The actuators 40 e to 40 h each incorporate one of the driver 30 and theposition sensor 50. Positions of the wires W5 to W8 are detected by theposition sensors 50 of the actuators 40 e to 40 h and these detectionvalues are outputted to the PC 300C.

The PC 300C is equipped with a communications interface 310, whichincludes the functions of the reference value input section 10, and thecontrol section 20.

The communications interface 310 receives detection values of theposition sensors 50 that are inputted from the finger-form robot 300Aand the finger-form robot 300B, and outputs the detection values to thecontrol section 20. The communications interface 310 outputs values ofacceleration for controlling the actuators 40 a to 40 h of thefinger-form robot 300A and finger-form robot 300B, which are inputted tothe communications interface 310 from the control section 20, to thefinger-form robot 300A and the finger-form robot 300B.

In the case of the position/force controller 1 that realizes thebolt-turning learning and reproduction function, a coordinate conversionexpressed as in Expression (4) is defined at the control section 20.Consequently, control of the finger-form robot 300B is executed inaccordance with operations of the respective finger portions sampled atthe finger-form robot 300A.

Thus, when a human performs operations to turn a bolt with thefinger-form robot 300A serving as the master device, these operationsmay be realized and the bolt may be turned by the finger-form robot 300Bserving as the slave device. At the same time, forces acting on thefinger-form robot 300B from the bolt are reproduced at the finger-formrobot 300A by a bilateral control function. That is, reaction forces thesame as if the finger of the human was actually turning the bolt arereproduced by the actuators 40 a to 40 d at the finger of the humanperforming the operations to turn the bolt.

(Movement Sampling Function)

Now, a sampling function of human movements to be realized by thepresent invention is described in detail.

As described for the structural example of the position/force controller1 that realizes the bolt-turning learning and reproduction functionaccording to FIG. 11, a robot with a mechanism corresponding to afunction of the human body is constructed, the robot is made to trackthat function of the human body, and a time series of operations at thistime is detected. Thus, human movements may be sampled.

For example, in the case of the finger-form robot 300A shown in FIG. 11,the human moves their finger and operations to turn a bolt are tracked.Positions of the wires W1 to W4 or the wires W5 to W8 while the fingermechanism portion 310A is moving are detected by the position sensors 50in a time series, and these positions are stored in a storage device.

Instead of detection results of the positions of the wires W1 to W4 orthe wires W5 to W8, respective values for calculating state values thatare obtained as coordinate conversion results in the control section 20(that is, the calculated values at the left side of Expression (4) intime series) may be stored in the storage device.

FIG. 12A and FIG. 12B are schematic diagrams showing informationexamples in which sampling results of a movement are stored. FIG. 12Ashows a case in which a time series of positions of the wires W1 to W4is stored, and FIG. 12B shows a case in which coordinate conversionresults according to Expression (4) are stored.

Referring to FIG. 12A, for example, a time series of positions of wireW1 is stored, with position p1 at time t1, position p2 at time t2,position p3 at time t3, etc.

Referring to FIG. 12B, for example, a time series of values of thecoordinate conversion result x″_(a1) is stored, with coordinateconversion result q1 at time t1, coordinate conversion result q2 at timet2, coordinate conversion result q3 at time t3, etc.

Thus, if a human performs an operation (movement) with their finger justonce, the operation (movement) of the bolt-turning learning andreproduction function or the like may subsequently be reproduced by arobot even without a human performing the operation (movement) withtheir finger.

(Realizing an Adaptable Function)

Now, realization of an adaptable function, which is enabled by thepresent invention, is described.

The term “realizing an adaptable function” means, when human movementshave been sampled by a movement sampling function as described above,adaptively realizing the sampled function even when an object differsfrom the object at the time of movement sampling.

Of the coordinate conversions shown in Expression (7) and Expression(8), computations that obtain vectors of force for calculating statevalues in the force domain are employed for realizing an adaptablefunction in the present embodiment. That is, in realizing an adaptablefunction, inputs according to the purpose of realizing the adaptablefunction are used in the coordinate conversions shown in Expression (7)and Expression (8), whereas other inputs are substantially set to zero.Thus, state values are calculated by a subset of the elements of thecoordinate conversion. Using this technique, control energy isdistributed to one or both of speed or position energy and force energy,and an adaptable function that is not entirely the same as at the timeof the movement sampling is realized.

Specifically, a coordinate conversion for realizing an adaptablefunction in the present embodiment can be expressed as in Expression(9).

$\begin{matrix}{\begin{pmatrix}f_{\tau\; 1} \\f_{\tau\; 2} \\f_{\tau\; 3} \\f_{t\; 2}\end{pmatrix} = {\begin{pmatrix}1 & {- 1} & {- 1} & {- 1} \\0 & 1 & {- 1} & {- 1} \\0 & 0 & 1 & {- 1} \\4 & 2 & 1 & 1\end{pmatrix}\begin{pmatrix}f_{5} \\f_{6} \\f_{7} \\f_{8}\end{pmatrix}}} & (9)\end{matrix}$

Below, realizing an adaptable function is described taking the devicedescribed in “Structural Example of the Position/Force Controller 1Realizing the Bolt-Turning Learning and Reproduction Function” accordingto FIG. 11 as an example.

FIGS. 13A to 13I are descriptive diagrams showing an overview ofrealizing the adaptable function.

Firstly, as shown in FIG. 13A to FIG. 13C, human operations (movements)to turn a bolt with the position/force controller 1 shown in FIG. 11 aresampled and time series of at least one of, for example, positions orforces of the wires W1 to W4 or the wires W5 to W8 shown in FIG. 12A arestored.

The position/force controller 1 sequentially reads out the time seriesof the at least one of positions and forces of the wires W1 to W4 or thewires W5 to W8 from the storage device. Using these values as referencevalues, the coordinate conversion of Expression (8) is sequentiallyapplied for the finger-form robot 300B that serves as a slave device,controlling the actuators 40 e to 40 f. At this time, the bolt that isin place is a bolt X the same as the bolt at the time of the sampling ofhuman operations (movements) to turn a bolt.

Accordingly, as shown in FIG. 13D to FIG. 13F, the stored operations ofthe master device represented by the wires W1 to W4 or the wires W5 toW8 are reproduced and the bolt X may be turned and detached in the samemanner as at the time of sampling of human operations (movements) toturn a bolt.

In this case, the bolt in place is a bolt Y with a different diameter,shape or the like from the bolt at the time of the sampling of humanoperations (movements) to turn a bolt.

At this time, the position/force controller 1 sequentially executes thecoordinate conversion in Expression (9) using only the positions of thewires W5 to W8 detected by the position sensors 50 of the finger-formrobot 300B, and not using the time series of positions of the wires W1to W4 or wires W5 to W8 that have been stored in the storage device.

State values are calculated using values of f_(τ1), f_(τ2), f_(τ3) andft2 obtained by the coordinate conversion of Expression (9), and theactuators 40 e to 40 h are controlled in accordance with the calculatedstate values.

Accordingly, as shown in FIG. 13G to FIG. 13I, the function may beadaptably realized by sequential calculation of state values in theforce domain, for the bolt Y that has the different diameter, shape orthe like from bolt X.

Thus, a function with high adaptability to environmental changes such asdifferences in an object and the like may be realized by applying thebasic principle of the present invention.

(Specific Example of Function Replacement)

Plural coordinate conversions defined by the function-dependentforce/speed distribution conversion block FT are stored in advance inthe basic structure of the position/force controller 1 shown in FIG. 8.The function being realized by the position/force controller 1 may bereplaced by replacing the coordinate conversion set in thefunction-dependent force/speed distribution conversion block FT.

FIG. 14 is a schematic diagram showing structures of the position/forcecontroller 1 that can replace a function.

The position/force controller 1 shown in FIG. 14 differs from theposition/force controller 1 shown in FIG. 8 in being provided with astorage section 60 that stores plural coordinate conversionsrepresenting functions.

In accordance with a function that is to be realized, the controlsection 20 reads one of coordinate conversions T1 to Tk (k is an integerthat is at least 1) stored in the storage section 60, and sets thatcoordinate conversion in the function-dependent force/speed distributionconversion block FT.

Thus, the position/force controller 1 may be configured to be capable ofappropriately realizing the function that is the objective among theplural prepared functions.

This position/force controller 1 is particularly useful in a case inwhich plural functions are to be realized by one of the control section20, a case in which plural robots are to be controlled by one of thecontrol section 20, or the like.

(Scaling Function)

The position/force controller 1 described above may realize scalingfunctions of position, force and time.

The term “scaling function” means a function that magnifies or reducesthe scale of positions, forces or times of outputs of controls thatserve as a reference. With a scaling function, for example, themagnitude of movements of a master device may be reduced and reproducedby a slave device, the strength (force) of movements of a master devicemay be strengthened and reproduced by a slave device, or the speed ofmovements of a master device may be lowered and reproduced by a slavedevice. By using a scaling function on information of at least one ofpositions and forces stored in a storage device, for example, themagnitudes of stored movements may be reduced and reproduced by a slavedevice or strengths (forces) of stored movements may be strengthened andreproduced by a slave device.

Below, a structural example for realizing a scaling function isdescribed.

(Force-Sense Transmission Function with Scaling)

A coordinate conversion at the function-dependent force/speeddistribution conversion block FT according to FIG. 2 for a case ofrealizing a force-sense transmission function with scaling can beexpressed as in the following Expressions (10) and (11).

$\begin{matrix}{\begin{pmatrix}{\overset{.}{x}}_{p} \\{\overset{.}{x}}_{f}\end{pmatrix} = {\begin{pmatrix}1 & {- \alpha} \\1 & \beta\end{pmatrix}\begin{pmatrix}{\overset{.}{x}}_{m} \\{\overset{.}{x}}_{s}\end{pmatrix}}} & (10) \\{\begin{pmatrix}f_{p} \\f_{f}\end{pmatrix} = {\begin{pmatrix}1 & {- \alpha} \\1 & \beta\end{pmatrix}\begin{pmatrix}f_{m} \\f_{s}\end{pmatrix}}} & (11)\end{matrix}$

With the coordinate conversion shown in Expression (10) and Expression(11), positions of a slave device are magnified by α (α is a positivenumber) and transmitted to a master device, and forces at the slavedevice are magnified by β (β is a positive number) and transmitted tothe master device.

This scaling function makes, for example, delicate tasks such assurgical operations, microassembly and the like and large-scale taskssuch as construction work, extravehicular activities in space and thelike possible.

(Force-Sense Transmission Function with Position Limiting by Scaling)

A coordinate conversion at the function-dependent force/speeddistribution conversion block FT according to FIG. 2 for a case ofrealizing a force-sense transmission function with position limiting byscaling can be expressed as in the following Expressions (12) to (15).

When realizing this function, it is appropriate to take account of thefollowing conditions:

-   -   Continuity even in the speed dimension (a Jacobian matrix is        required)    -   Positions beyond a limit are a monotonically increasing function        of an original position (stability is required)    -   If x_(s)<a, then x_(s)=x_(shat) or x_(s)≈x_(shat) (x_(shat) is a        parameter included in Expression (14) and Expression (15) at the        function-dependent force/speed distribution conversion block FT        (control performance in a stable region must be assured)    -   There is a saturation function (position-limiting must be        realized)        As an alternative function that satisfies these conditions, an        arctangent function may be employed.        IF Xs<a,

$\begin{matrix}{\begin{pmatrix}{\overset{.}{x}}_{p} \\{\overset{.}{x}}_{f}\end{pmatrix} = {\begin{pmatrix}1 & {- 1} \\1 & 1\end{pmatrix}\begin{pmatrix}{\overset{.}{x}}_{m} \\{\overset{.}{x}}_{s}\end{pmatrix}}} & (12) \\{\begin{pmatrix}f_{p} \\f_{f}\end{pmatrix} = {\begin{pmatrix}1 & {- 1} \\1 & 1\end{pmatrix}\begin{pmatrix}f_{m} \\f_{s}\end{pmatrix}}} & (13)\end{matrix}$IF Xs≥a,

$\begin{matrix}{\begin{pmatrix}{\overset{.}{x}}_{p} \\{\overset{.}{x}}_{f}\end{pmatrix} = {\begin{pmatrix}{1 - e^{b{({{\hat{x}}_{s} - a})}}} \\{1\mspace{14mu} e^{b{({{\hat{x}}_{s} - a})}}}\end{pmatrix}\begin{pmatrix}{\overset{.}{x}}_{m} \\{\overset{.}{x}}_{s}\end{pmatrix}}} & (14) \\{\begin{pmatrix}f_{p} \\f_{f}\end{pmatrix} = {\begin{pmatrix}{1 - e^{b{({{\hat{x}}_{s} - a})}}} \\{1\mspace{14mu} e^{b{({{\hat{x}}_{s} - a})}}}\end{pmatrix}\begin{pmatrix}f_{m} \\f_{s}\end{pmatrix}}} & (15)\end{matrix}$

If the coordinate conversions shown in Expression (12) to Expression(15) are used, then when the position of the slave device is less thana, the coordinate conversions in Expressions (12) and (13) are employed.Thus, the slave device is controlled to the same position as the masterdevice. On the other hand, when the position of the slave device is atleast a, the coordinate conversions in Expressions (14) and (15) areemployed. Thus, the scaling function is active and the slave device iscontrolled such that its position does not go beyond (1/b+a).

This scaling function makes, for example, protecting organs in surgicaloperations and avoiding breakage of physical bodies possible.

(Force-Sense Transmission Function Using Scaling in Frequency Ranges)

FIG. 15 is a schematic diagram showing an overview of controlling theforce-sense transmission function using scaling in frequency ranges.

In FIG. 15, the outputs of a master device and a slave device arerespectively passed through a high-pass filter (HPF) and a low-passfilter (LPF), and then inputted to the function-dependent force/speeddistribution conversion block FT.

In the function-dependent force/speed distribution conversion block FT,a coordinate conversion for a high-frequency region is applied to theoutputs of the master device and slave device that have passed throughthe high-pass filter, and a coordinate conversion for a low-frequencyregion is applied to the outputs of the master device and slave devicethat have passed through the low-pass filter. That is, thefunction-dependent force/speed distribution conversion block FT splitsthe inputs from the master device and the slave device into signals inthe high-frequency region and the low-frequency region and appliescoordinate conversions corresponding to the respective frequencyregions.

As shown in FIG. 15, the coordinate conversions at thefunction-dependent force/speed distribution conversion block FT for acase of realizing a force-sense transmission function using scaling infrequency ranges can be expressed as in the following Expressions (16)to (19).

For the Low-Frequency Region,

$\begin{matrix}{\begin{pmatrix}{\overset{.}{x}}_{p} \\{\overset{.}{x}}_{f}\end{pmatrix} = {\begin{pmatrix}1 & {- 1} \\1 & 1\end{pmatrix}\begin{pmatrix}{\overset{.}{x}}_{m} \\{\overset{.}{x}}_{s}\end{pmatrix}}} & (16) \\{\begin{pmatrix}f_{p} \\f_{f}\end{pmatrix} = {\begin{pmatrix}1 & {- 1} \\1 & 1\end{pmatrix}\begin{pmatrix}f_{m} \\f_{s}\end{pmatrix}}} & (17)\end{matrix}$For the High-Frequency Region,

$\begin{matrix}{\begin{pmatrix}{\overset{.}{x}}_{p} \\{\overset{.}{x}}_{f}\end{pmatrix} = {\begin{pmatrix}1 & {- \alpha} \\1 & \beta\end{pmatrix}\begin{pmatrix}{\overset{.}{x}}_{m} \\{\overset{.}{x}}_{s}\end{pmatrix}}} & (18) \\{\begin{pmatrix}f_{p} \\f_{f}\end{pmatrix} = {\begin{pmatrix}1 & {- \alpha} \\1 & \beta\end{pmatrix}\begin{pmatrix}f_{m} \\f_{s}\end{pmatrix}}} & (19)\end{matrix}$

If the coordinate conversions shown in Expression (16) to Expression(19) are used, the coordinate conversions in Expressions (16) and (17)are employed for the low-frequency region. Thus, the slave device iscontrolled to the same position as the master device. The coordinateconversions in Expressions (18) and (19) are employed in thehigh-frequency region. Thus, positions of the slave device are magnifiedby a (α is a positive number) and transmitted to the master device, andforces at the slave device are magnified by β (β is a positive number)and transmitted to the master device.

By this scaling function, a sensation when, for example, the slavedevice passes through or breaks a body is strengthened and transmittedto the master device.

(Reproducing a Function Using Time Scaling)

In reproduction of a function with the position/force controller 1, timescaling may be realized by applying thinning to information representingthe function that has been learned and stored (for example, the timeseries of data representing sampling results of movements that are shownin FIG. 12A and FIG. 12B), or by specifying target values byinterpolation or the like.

To be specific, a stored function (operation) may be reproduced at ahigher speed by thinning information representing the function that hasbeen learned and stored and then using the thinned information as targetvalues of computation at the ideal force origin block FC or the idealspeed (position) origin block PC. Similarly, a stored function(operation) may be reproduced at a lower speed by interpolatinginformation representing the function that has been learned and storedand then using the interpolated information as target values.

Accordingly, if a stored function (operation) is to be reproduced at ahigher speed, a slow and precise operation may be performed at the timeof movement sampling. Thus, a fast and precise operation may beperformed at the time of reproduction.

Furthermore, if a stored function (operation) is reproduced at a lowerspeed, an operation that is usually carried out quickly may bereproduced slowly. For example, in rehabilitation of patients sufferingfrom the after-effects of injuries or the like, training operations maybe reproduced in accordance with the patients' conditions.

Specific Application Examples

Various application examples may be realized by using the functionsdescribed in the embodiment above singly or in combination.

(Application to an Electronic Game)

FIG. 16 is a schematic diagram showing a situation in which theforce-sense transmission function is realized with a body in a virtualspace.

FIG. 16 shows an example in which the present invention is applied to anelectronic game (for example, a game of arm wrestling or the like) thattransmits forces and senses between an operator and an object in avirtual space.

FIG. 17 is a schematic diagram showing an overview of control when theforce-sense transmission function is realized with the body in thevirtual space.

As shown in FIG. 16, an operator Rm controls a controller (an actuator)Ct that serves as a master device.

Correspondingly, a virtual body Xa (in this example, an arm of a virtualperson Va) moves to match movements of the controller Ct.

When the virtual body Xa touches a virtual body Xb (in this example, anarm of a virtual person Vb), as shown in FIG. 17, contact between thevirtual body Xa and the virtual body Xb acts as a slave device. Positionand force energy are distributed and converted in correspondence withvariables in the virtual space and variables in real space.

During this, force-sense transmission is conducted between thecontroller Ct and the virtual body Xa; forces and senses experienced bythe virtual person Va who is arm wrestling with the virtual personal Vbare transmitted.

Thus, the present invention may be applied to an electronic game inwhich objects and forces interact in a virtual space.

An object in a virtual space may be an object that is virtuallygenerated, a real object that is modeled in the virtual space, or thelike.

In accordance with this application example, a situation of fightingwith an enemy character in a virtual space, a situation of driving in avirtual vehicle along a race course constituted of various road surfacesin a virtual space, a situation of moving a body in a virtual space andso forth may be realized with high levels of realism.

Because a controller Ct may function as a master device by receivingcontrol signals for an actuator, there is no need to install a programor a large number of sensors in the controller Ct. Thus, the controllerCt may be realized cheaply with a simple structure.

In FIG. 16, the controller Ct that serves as the master device is shownas a lever-type device, but the specific form of the controller Ct maybe variously altered in accordance with the type of electronic game andthe like. For example, a controller may be formed that is provided withan inner tube and an outer tube disposed coaxially, in which the outertube may be turned around the inner tube by an actuator. In this case,depending on the details of the electronic game, the operator Rm mayperform operations of turning the outer tube and the actuator maycontrol turning forces and turning amounts of the outer tube by theforce-sense transmission function.

(Application to Surgical Forceps)

FIGS. 18A to 18D are schematic diagrams showing a situation in which thepresent invention is applied to surgical forceps.

As shown in FIG. 18A, a force-sense transmission function may berealized between an operator Rm controlling a master device andactuators of a forceps that serves as a slave device.

In this case, if simple force-sense transmission is performed, then whenthe master device is controlled to move upward relative to a pivot, asshown in FIG. 18B, the forceps of the slave device is also displacedupward. Thus, movements may be opposite to human intuition.

That is, when an original forceps is being manipulated, because theforceps is a rigid object, a control portion of the forceps iscontrolled to move upward when the operator intends to move the distalend of the forceps downward. Therefore, the movement in FIG. 18B is anopposite movement to the movement when an original forceps that is arigid object is being manipulated.

Accordingly, as shown in FIG. 18C, the forceps of the slave device maybe controlled to a state of being displaced downward when the masterdevice is controlled to move upward relative to a pivot, as shown inFIG. 18D, by a mirror conversion being applied to the coordinateconversion at the function-dependent force/speed distribution conversionblock FT. That is, the movement is the same as that when an originalforceps that is a rigid object is being manipulated.

Therefore, controls that are intuitive for the operator are possible.

By applying this mirror conversion, the operator may flexibly specify aviewpoint relative to an object and adjust the viewpoint to a state inwhich control is easy for the operator.

Moreover, scaling may be applied to the coordinate conversion in thefunction-dependent force/speed distribution conversion block FT to whichthe mirror conversion has been applied.

For example, if scaling is applied to reduce the scale of control of themaster device, a conversion to delicate movements of the forceps ispossible, which may facilitate difficult surgical operations requiringhigh levels of caution at the heart, the brain and the like.

In this case, the scaling ratio may be a fixed ratio, or alternativelymay be a ratio that varies depending on conditions, or the like.

For example, in a heart operation, the ratio of operations of the masterdevice and the slave device may be set to 1:1 or the like at an openheart stage, but at a stage in which the heart is closed up, the scalingratio may be reduced such that operations of the slave device are shrunkin scale relative to operations of the master device.

(Application to a Master Device and Slave Device Connected by Wireless)

FIG. 19 is a schematic diagram showing a master device and a slavedevice that are connected by wireless.

Because the master device and slave device are connected by wireless andcommunicate at high-speed, a master/slave system with high real-timeperformance and excellent portability may be realized.

That is, various functions such as the force-sense transmission functionand the like may be realized at the slave device that is connected bywireless with the master device.

FIG. 20 is a block diagram showing structures of a slave device 400 thatis connected by wireless to a master device.

As shown in FIG. 20, the slave device 400 is equipped with a switchgroup 401, an LED group 402, a host computer unit 403, a wireless unit404, a motor unit 405, a gearing mechanism 406, an end effector 407, ameasurement unit 408, a recording and display unit 409, and a powersupply unit 410.

The switch group 401 is provided with plural rotating-type switches andon/off switches, and accepts various settings of the slave device 400.Specifically, rotating-type switches are used to adjust scaling ratiosof the slave device 400. In the present embodiment, position scaling andforce scaling may be respectively separately set by rotating-typeswitches. On/off switches are used to set states of the slave device400. For example, a first on/off switch functions as a power supplyswitch. When the first on/off switch is set to on, a power supplycircuit 410 b is put into an electrified state and electric power from asignal battery 410 a is supplied to a control system of the slave device400. A second on/off switch functions as a servo motor switch. When thesecond on/off switch is set to on, a power supply of a motor driver 405b is turned on and a supply of power to a servo motor 405 d is put intoa standby state. A third on/off switch functions as a control switch.When the third on/off switch is set to on, a control program is executedand the supply of power (driving) to the servo motor 405 d is started.Control of the slave device 400 in the master/slave system is started bythe first, second and third on/off switches being set to on in thisorder.

The LED group 402 expresses various states of the slave device 400 (anon/off state of the power supply and the like) by lighting states.

The host computer unit 403 is equipped with a program writing circuit403 a and a microcontroller 403 b.

The program writing circuit 403 a writes programs to the microcontroller403 b.

The microcontroller 403 b controls the slave device 400 in accordancewith a program written by the program writing circuit 403 a.Specifically, the microcontroller 403 b communicates by wireless withthe master device while controlling positions and forces against anobject or conducting measurements of the actions of an object.

The wireless unit 404 is equipped with an antenna 404 a and a wirelesscommunications circuit 404 b.

The antenna 404 a receives wireless signals from the master device andtransmits wireless signals from the slave device 400 to the masterdevice.

The wireless communications circuit 404 b demodulates wireless signalsinputted from the antenna 404 a and outputs demodulated control signalsto the host computer unit 403. The wireless communications circuit 404 balso modulates control signals inputted from the host computer unit 403and outputs them to the antenna 404 a.

The motor unit 405 is equipped with a D/A converter 405 a, the motordriver 405 b, a driving battery 405 c and the servo motor 405 d.

The D/A converter 405 a converts digital signals (control signals)inputted from the host computer unit 403 to analog signals.

The motor driver 405 b drives the servo motor 405 d in response toanalog signals inputted from the D/A converter 405 a.

The driving battery 405 c supplies power for driving the servo motor 405d.

The servo motor 405 d controls positions and forces of the end effector407, via the gearing mechanism 406, in response to driving signals fromthe motor driver 405 b.

The gearing mechanism 406 decelerates operations of the motor driver 405b, modifying the torque, and transmits the operations to the endeffector 407.

The end effector 407 constitutes an interface that interacts directlywith an object. In the present embodiment, a fork-shaped tool isprovided to serve as the end effector 407.

The measurement unit 408 is equipped with an encoder 408 a and a linereceiver 408 b.

The encoder 408 a measures operations of the servo motor 405 d (turningangles) and converts the same to electronic signals.

The line receiver 408 b outputs the measurement result electronicsignals outputted from the encoder 408 a to the host computer unit 403as differential signals. A speed sensor, an acceleration sensor or analternative estimation method may be substituted in order to achieve anapplication of the slave device 400.

The recording and display unit 409 is equipped with a recording anddisplay circuit 409 a, a storage medium 409 b and a display 409 c.

In response to commands from the host computer unit 403, the recordingand display circuit 409 a stores control information on positions andforces of the servo motor 405 d, scaling ratios, electromagneticconditions of the wireless connection, and information relating to thedevice and a body being touched such as times and the like in thestorage medium 409 b, and displays the same at the display 409 c. Therecording and display circuit 409 a also reads information stored in thestorage medium 409 b and outputs the information to the host computerunit 403.

In response to control by the recording and display circuit 409 a, thestorage medium 409 b stores control information on positions and forcesof the servo motor 405 d in operations of the slave device 400, scalingratios, electromagnetic conditions of the wireless connection, andinformation relating to the device and a body being touched such astimes and the like. The information stored in the storage medium 409 bmay be read out for data processing. Information for reproducingoperations at the slave device 400 may be stored in the storage medium409 b, and the microcontroller 403 b may reproduce the operations byreading and executing this information.

The power supply unit 410 is equipped with the signal battery 410 a andthe power supply circuit 410 b.

The signal battery 410 a supplies electric power to the control systemof the slave device 400.

The power supply circuit 410 b controls the electric power beingsupplied to the control system of the slave device 400 from the signalbattery 410 a.

The master device and slave device may be connected by communications bywireless, and alternatively may be connected by communications by wire,via a wire communications port (see FIG. 19).

According to this structure, when the end effector 407 touches an object(a ball or the like) in response to movements of the master device,positions and reaction forces of the servo motor 405 d are transmittedfrom the slave device 400 to the master device as position and forceinformation. Correspondingly, a function that transmits force and senseof the slave device 400 or the like may be realized at the masterdevice.

Now, a data transmission process between the master device and the slavedevice is described.

FIG. 21 is a diagram showing a data structure for high-speedcommunications between the master device and the slave device. As shownin FIG. 21, in the present application example, information on aposition and a force is expressed as a total of 64 bits of data(respective 32-bit “float” type variables), which are to be propagatedat high speed.

Accordingly, the position and force data is first divided into 16 datablocks. Therefore, each data block has an information quantity of fourbits. To identify the order of the 16 four-bit blocks, four-bit data IDsare appended to the heads of the data blocks. Thus, 16 one-byte datablocks, each constituted by a four-bit data ID and four bits of actualdata, are created, providing a total of sixteen bytes of data.

This is propagated between the master device and the slave device by thefollowing procedure.

FIG. 22 is a timing chart showing a communication sequence between themaster device and slave device that are connected by wireless.

In the master/slave system according to the present application example,in order to speed up processing, a control program is directly installedin an internal memory control unit (MCU) at each of the master deviceand the slave device.

In FIG. 22, a transmission side host (a processor or the like at thetransmission side) transfers the 16 data blocks shown in FIG. 21 to atransmission side module (the communications interface or the like atthe transmission side), one block at a time. Here, 100 μs is sufficientto transfer each block; a transfer rate between the transmission sidehost and the transmission side module of around 1 Mbps can be assured.

Then, wireless communications are conducted between the transmissionside module and a reception side module (the communications interface orthe like at the reception side). A propagation rate along the wirelesscommunications path of around 1 Mbps can be assured; approximately 1.2ms is sufficient to propagate the 16 data blocks.

Between the reception side module and a reception side host (a processorat the reception side or the like), a propagation rate of around 1 Mbpscan be assured; 100 μs is sufficient to transfer each 1-byte data block.

Thus, propagation of the 16 bytes of data from the start of output ofdata by the transmission side host to the reception side host is around4.5 ms.

Thus, in the present application example, a control program is directlyinstalled in each internal MCU, position and force information are eachdivided into eight blocks of four bits and propagated to thecommunications module, and a packet size in the wireless communicationspath is reduced to 16 bytes.

In a conventional protocol such as, for example, UCP/IP, the packet sizeis 24 bytes because of various kinds of header information and the like.In contrast, in the present application example, the required packetsize is 16 bytes.

Therefore, the master/slave system that is connected by wireless may berealized as a system with high real-time performance and excellentportability.

(Application to Creating a Database of Operations)

FIG. 23 is a schematic diagram showing an overview of creating adatabase of human operations.

As mentioned above, a speed (position) of an actuator is expressed by anintegral of acceleration, and a force of the actuator is expressed as aproduct of weight and acceleration.

Therefore, in the present invention, a human operation may be quantifiedand sampled from at least one of information on positions of an actuatorand information on forces that is obtained on the basis of informationon positions of the actuator.

As shown in FIG. 23, operations performed by an operator are measured bya force-sense transmission function according to the present invention.

That is, when the operator controls a master device, an operationperformed by the operator is broken down by computations at thefunction-dependent force/speed distribution conversion block FT, theideal force origin block FC and the ideal speed (position) origin blockPC, and this operation may be realized.

By operations by a plural number of humans being broken down bycomputations at the function-dependent force/speed distributionconversion block FT, the ideal force origin block FC and the ideal speed(position) origin block PC and the results being acquired, informationprocessed in each of these blocks may be accumulated in a database DB.

Thus, by integration processing being applied to the information ofoperations by plural humans accumulated in the database, characteristicsof operations by individual people (individual styles, comparisonsbetween individuals and the like) may be sampled and quantified.

Therefore, by integration processing being applied to operationinformation of experienced and inexperienced people or the like, tacitknowledge, skills, knowhow and the like may be sampled to produceobjective numerical data.

(Application Using Offsetting in Function-Dependent Force/SpeedDistribution Conversion)

FIG. 24 is a schematic diagram showing an overview of offsetting infunction-dependent force/speed distribution conversion.

Offsetting in function-dependent force/speed distribution conversionenables tracking of changes in an object by increasing or decreasingpredetermined constants corresponding to position and force energy inthe results of conversion at the function-dependent force/speeddistribution conversion block FT.

That is, as shown in FIG. 24, a position of the object measured by anexternal sensor D or the like may be applied as an offset in thefunction-dependent force/speed conversion.

For example, in the case of a heart operation, because the object—theheart—is continuously beating, a position of the surface of the heart ismeasured by the external sensor D and the measured changes in positionare applied as offsets in the function-dependent force/speed conversion.Thus, automatic tracking of the heart surface by a slave device (forexample, a forceps or the like) may be realized.

At this time, by the offset being applied to a force-sense transmissionfunction, both force-sense transmission and automatic tracking of theposition of the heart surface are possible.

Therefore, the effects of displacements due to beating of the heart on asurgeon performing the operation may be moderated and more precise workis possible.

(Effects)

As described above, according to a position/force controller inaccordance with a first aspect of the present invention, afunction-dependent force/speed distribution converter, on the basis ofspeed or position information and force information corresponding to theinformation relating to the position and on the basis of informationserving as a reference for control, performs a conversion to distributecontrol energy to speed or position energy and force energy inaccordance with a function that is being realized. A position controlamount calculator calculates a speed or position control amount on thebasis of the speed or position energy distributed by thefunction-dependent force/speed distribution converter. A force controlamount calculator calculates a force control amount on the basis of theforce energy distributed by the function-dependent force/speeddistribution converter. An integrator integrates the speed or positioncontrol amount with the force control amount and, in order to return anoutput of the integration to the actuator, performs a reverse conversionon the speed or position control amount and the force control amount anddetermines an input to the actuator. Thus, the speed or position energyand the force energy can be respectively separately controlled.

Therefore, the distribution of control energy to speed or positionenergy and force energy by the function-dependent force/speeddistribution converter may be variously altered in accordance withfunctions.

Consequently, by settings of the function-dependent force/speeddistribution converter being altered in accordance with a function thatis an objective, a technique for appropriately realizing human-likemovements by a robot may be provided.

According to a position/force controller in accordance with a secondaspect of the present invention, a function-dependent force/speeddistribution converter, on the basis of speed or position informationand force information corresponding to the information relating to theposition and on the basis of information serving as a reference forcontrol that is acquired in advance, performs a conversion to distributecontrol energy to at least one of speed or position energy and forceenergy in accordance with a function that is being realized. A positioncontrol amount calculator calculates at least one of a speed or positioncontrol amount and a force control amount energy on the basis of atleast one of the speed or position energy and the force energydistributed by the function-dependent force/speed distributionconverter. An integrator integrates the speed or position control amountwith the force control amount and, in order to return an output of theintegration to the actuator, performs a reverse conversion on the speedor position control amount and the force control amount and determinesan input to the actuator.

Therefore, because the control amounts of speed (position) or force arecalculated on the basis of the information serving as a reference forcontrol that is acquired in advance, a function acquired in advance maybe reproduced.

According to a position/force controller in accordance with a thirdaspect of the present invention, the function-dependent force/speeddistribution converter, on the basis of speed or position informationand force information corresponding to the information relating to theposition and on the basis of information serving as a reference forcontrol, performs a conversion to distribute control energy to speed orposition energy and force energy by a conversion that is specified tomatch a function that is being realized. A position control amountcalculator calculates a speed or position control amount on the basis ofthe speed or position energy distributed by the function-dependentforce/speed distribution converter. A force control amount calculatorcalculates a force control amount on the basis of the force energydistributed by the function-dependent force/speed distributionconverter. An integrator integrates the speed or position control amountwith the force control amount and, in order to return an output of theintegration to the actuator, performs a reverse conversion on the speedor position control amount and the force control amount and determinesan input to the actuator. A scaler applies scaling of at least one ofposition, force and time to outputs of the actuator.

Therefore, because the control energy is distributed to the speed orposition energy and the force energy by a conversion that is specifiedto match the function being realized, the function may be realized inaccordance with a particular objective. Moreover, because scaling ofposition, force and time may be applied to the outputs of the actuatordue to the scaler being interposed at a location on a control path, themagnitude of movements of the actuator may be reduced, the strength(force) of movements may be strengthened, or the speed of movements maybe lowered.

EXPLANATION OF REFERENCE NUMERALS

S control object system, FT function-dependent force/speed distributionconversion block (function-dependent force/speed distributionconverter), FC ideal force origin block (force control amountcalculator), PC ideal speed (position) origin block (position controlamount calculator), IFT reverse conversion block (integrator), 1position/force controller, 10 reference value input section, 20 controlsection, 30 driver, 40 actuator, 50 position sensor (position detector),60 storage section.

The invention claimed is:
 1. A position/force controller comprising: anactuator; a driver that drives the actuator; a function-dependentforce/speed distribution conversion unit that, based on speed orposition information and force information corresponding to informationrelating to a position based on an action of the actuator and based oninformation serving as a reference for control, performs a conversion todistribute control energy to at least one of speed or position energyand force energy in accordance with a function that is being realized bythe position/force controller, thereby converting real spaceinformation, in which a speed or position and a force are related toeach other, to virtual space information, in which a speed or positionand a force are independent of each other; a control amount calculationunit that calculates at least one of a speed or position control amountand a force control amount based on at least one of the speed orposition energy and the force energy distributed by the functiondependent force/speed distribution conversion unit; and an integrationunit that uses the speed or position control amount and the forcecontrol amount as an input and, in order to return a processing resultthereof to the actuator, performs a reverse conversion on the speed orposition control amount and the force control amount from the virtualspace information to the real space information and determines an inputto the actuator, wherein the driver drives the actuator based on theinput determined by the integration unit.
 2. The position/forcecontroller according to claim 1, wherein: the function-dependentforce/speed distribution conversion unit, based on the speed or positioninformation and the force information corresponding to the informationrelating to the position and based on the information serving as areference for control, performs, as the conversion, a conversion todistribute control energy to speed or position energy and force energyby a conversion that is specified to match the function that is beingrealized by the position/force controller; the control amountcalculation unit comprises: a position control amount calculation unitthat calculates the speed or position control amount based on the speedor position energy distributed by the function dependent force/speeddistribution conversion unit; and a force control amount calculationunit that calculates the force control amount based on the force energydistributed by the function-dependent force/speed distributionconversion unit; and the position/force controller further comprises ascaling unit that applies scaling of at least one of position, force andtime to outputs of the actuator.
 3. A position/force control method fora position/force controller including an actuator and a driver thatdrives the actuator, the method comprising: a function-dependentforce/speed distribution conversion step of, based on speed or positioninformation and force information corresponding to information relatingto a position based on an action of the actuator and based oninformation serving as a reference for control, performing a conversionto distribute control energy to at least one of speed or position energyand force energy in accordance with a function that is being realized bythe position/force controller, thereby converting real spaceinformation, in which a speed or position and a force are related toeach other, to virtual space information, in which a speed or positionand a force are independent of each other; a control amount calculationstep of calculating at least one of a speed or position control amountand a force control amount based on at least one of the speed orposition energy and the force energy distributed in thefunction-dependent force/speed distribution conversion step; anintegration step of using the speed or position control amount and theforce control amount as an input and, in order to return a processingresult thereof to the actuator, performing a reverse conversion on thespeed or position control amount and the force control amount from thevirtual space information to the real space information and determiningan input to the actuator; and a driving step of driving the actuatorwith the driver based on the input determined in the integration step.4. The position/force control method according to claim 3, wherein: thefunction-dependent force/speed distribution conversion step, based onthe speed or position information and the force informationcorresponding to the information relating to the position and based onthe information serving as a reference for control, performs, as theconversion, a conversion to distribute control energy to speed orposition energy and force energy by a conversion that is specified tomatch the function that is being realized by the position/forcecontroller; and the control amount calculation step performs: a positioncontrol amount calculation step of calculating the speed or positioncontrol amount based on the speed or position energy distributed in thefunction-dependent force/speed distribution conversion step; and a forcecontrol amount calculation step of calculating the force control amountbased on the force energy distributed in the function-dependentforce/speed distribution conversion step; and the position/force controlmethod further comprises a scaling step of applying scaling of at leastone of position, force and time to outputs of the actuator.
 5. Anon-transitory computer readable storage medium having stored therein aprogram that is executable by a computer of a position/force controllerincluding an actuator and a driver that drives the actuator, the programbeing executable by the computer to cause the computer to realizefunctions comprising: a function-dependent force/speed distributionconversion function that, based on speed or position information andforce information corresponding to information relating to a positionbased on an action of the actuator and based on information serving as areference for control, performs a conversion to distribute controlenergy to at least one of speed or position energy and force energy inaccordance with an operation that is being realized by theposition/force controller, thereby converting real space information, inwhich a speed or position and a force are related to each other, tovirtual space information, in which a speed or position and a force areindependent of each other; a control amount calculation function thatcalculates at least one of a speed or position control amount and aforce control amount based on at least one of the speed or positionenergy and the force energy distributed by the function-dependentforce/speed distribution conversion function; an integration functionthat uses the speed or position control amount and the force controlamount as an input and, in order to return a processing result thereofto the actuator, performs a reverse conversion on the speed or positioncontrol amount and the force control amount from the virtual spaceinformation to the real space information and determines an input to theactuator; and a driving function that controls the driver to drive theactuator based on the input determined by the integration function. 6.The non-transitory computer readable storage medium according to claim5, wherein: the function-dependent force/speed distribution conversionfunction, based on the speed or position information and the forceinformation corresponding to the information relating to the positionand based on the information serving as a reference for control,performs, as the conversion, a conversion to distribute control energyto speed or position energy and force energy by a conversion that isspecified to match the operation that is being realized by theposition/force controller; the control amount calculation functioncomprises: a position control amount calculation function thatcalculates the speed or position control amount based on the speed orposition energy distributed by the function dependent force/speeddistribution conversion function; and a force control amount calculationfunction that calculates the force control amount based on the forceenergy distributed by the function-dependent force/speed distributionconversion function; and the storage medium further comprises a scalingfunction that applies scaling of at least one of position, force andtime to outputs of the actuator.